﻿#遍历字典时，默认是遍历字典里的键


# users_1={'age':'19','name':'liming','hobby':'programming'}
# for value in users_1.values():
# #     print(f'\nKey:{key.title()}')
#     print(f"Value:{value.title()}") 
# # print(users_1.keys())
alien_0={'color':'green','speed':'slow'}
# print(alien_0.get('points','Not found the "points" key'))
# river={'长江':'中国','亚马逊河':'巴西，哥伦比亚，玻利维亚，秘鲁','湄公河':'中国、缅甸、泰国、老挝、柬埔寨和越南'}
# for river_name,countries in river.items():
#     print(f"The {river_name} runs through {countries}")
# for river_name in river:
#     print(river_name)
# aliens_1=[]
# aliens_2=[]
# for times in range(20):
#     new_alien_1={'color':'green','speed':'slow','points':'5'}
#     # new_alien_2={'color':'blue','speed':'fast','points':'15'}
#     aliens_1.append(new_alien_1)
#     # aliens_2.append(new_alien_2)
# for times in aliens_1[:4]:
#     print(f"Total number of aliens:{len(aliens_1)}")
# print(alien_0.get('colo'))
D={'数学':101,'语文':202,'英语':203, '物理':204, '生物':206}
D['化学']=205
D['数学']=201
del(D['生物'])
print(D)

 
        
   